The invention relates generally to the field of roof ventilation systems, and more particularly to roof ridge ventilation systems using a matting material.
It has long been a common practice to provide ventilation to attics under gable roofs by installing a vent along the ridge of the roof. A slot or space is provided in the sheeting and roofing materials adjacent to each side of the ridge and extending along the length of the ridge. The slot allows hot air to escape by convection as well as by the suction created by wind blowing over the roof ridge.
To further enhance ventilation, soffit ventilators are typically installed under the eaves of an overhanging roof. Additional ventilators may be installed in the gable ends of the building. Fresh air from outside the structure enters the attic through perforations or slots in the soffit and gable ventilators. The entering fresh air tends to equalize the temperature and pressure of the air inside the attic with the ambient air outside the structure. This equalization reduces condensation of water vapor on the inside surfaces of the attic, thus reducing the formation of mildew and rot in the structure. Removal of the hot air from the attic also reduces the cost of air conditioning the building below the attic.
The roof ridge vent thus works in combination with soffit and gable vents to enable passive air ventilation. The exit of heated, stale air through the ridge vent by convection and wind suction is accompanied by the entry of fresh, cooler outside air through the soffit and gable vents.
The ridge vent must be capped to prevent entry of water from rain or snow, and preferably must also have some means to exclude dust and pests such as insects, birds and rodents. The simplest type of cap that has long been used is a metal hood spaced above the ridge slot and extending wider than the slot to exclude water. The metal hood may also include metal baffles, louvers or screens to exclude pests.
Other known cap structures utilize a porous material over the slot which permits the passage of air but excludes pests. The porous material is topped with the same roofing material as the rest of the roof, e.g., asphalt shingles. Materials which have been used include matrices of molded plastic, corrugated polyethylene sheets, open-cell plastic foam and various synthetic fiber materials such as nylon or polyester. These materials each have certain desirable properties, but also suffer from disadvantages such as lack of durability, inconvenient installation requirements and high cost.
It is an object of the invention to provide an improved roof ridge ventilation system using a mat made of randomly-aligned natural fibers laid on a polyester mesh fabric and joined by latex binding agents and heat cured to form a mat with varying mesh.
It is also an object of the invention to provide a mat that may be produced in rolls which are lightweight and easy to transport, and are easily installed by unrolling the mat along the length of the slot in the roof ridge, covering with cap shingles and fastening the shingles to the roof with standard roofing nails. Strips of the mat may be joined end-to-end to provide a continuous strip long the entire length of the roof ridge by using caulk to seal the ends of the strips together.
It is a further object of the invention to provide a roof ridge vent system which provides maximum flow of air while providing an effective barrier to water, dust and pests.
It is yet another object of the invention to provide an aesthetically-pleasing roof ridge vent.
It is a further object of the invention to provide a roof ridge vent system using a mat material which is more economical than synthetic mat materials.